Fire out of top of carb

[Eighty5ov]

It’s a Quadrajet, I replaced the needle and seat. Airhorn gasket. Now when I crank it up, it runs for 5 seconds and then shuts off and the next crank will shoot flame from the top of carb. Could I have put it together wrong? I took off power piston, float needle seat float assembly. Any help is appreciated, the engine ran great and was time. Didn’t touch distributor.

 

[dsteelejr]

Check your timing. Trying advancing it a little bit.

 

[fast 99]

Drop something into engine, piece of gasket under valve, crossed plug wires, very lean? Does it run smooth for those 5 seconds if not, check vacuum, broken valve spring, ect.
Even if there is excessive fuel it will need spark from somewhere. What else [if anything] was touched/done/ moved during the carb repair?

 

[GTX63]

If the engine ran fine before you pulled the carb, then it is pretty certain to be something to do with the carb. Pull it and break it down.
It isn't hard to push the float out of adjustment, bind a spring, misalign the needle, etc, or yes, drop something into the intake. Without video or being there, it sounds like it may be dumping fuel.

 

[Eighty5ov]

Drop something into engine, piece of gasket under valve, crossed plug wires, very lean? Does it run smooth for those 5 seconds if not, check vacuum, broken valve spring, ect.
Even if there is excessive fuel it will need spark from somewhere. What else [if anything] was touched/done/ moved during the carb repair?

I took off the top of the carb to get into the needle and seat. So power piston came off. The old gasket was torn apart. Accel pump off. Needle and seat. And the float assembly. Replaced the air horn gasket, needle and seat. Put everything back and tightened her up. Then it’ll start and run for about 5 seconds then die, and next crank I get flames out of top.

 

[Eighty5ov]

If the engine ran fine before you pulled the carb, then it is pretty certain to be something to do with the carb. Pull it and break it down.
It isn't hard to push the float out of adjustment, bind a spring, misalign the needle, etc, or yes, drop something into the intake. Without video or being there, it sounds like it may be dumping fuel.

I’ll take it apart and see what’s up.

 

[Eighty5ov]

I went over everything on the top end and found the carb mount bolts weren’t fully snug. Fired right up and running normal. But ran into another problem. Leak at fuel filter. Tightened it and it stripped. What would a guy suggest ?

 

[racprops]

How do you put out a fire in a carb?? Crank the engine with the coil disconnected, it will suck the flame out...after-all these are fire breathing engines...

Last question: a good carb shop may be able to put in a Heleocoil or retread it for a larger filter.

Rich

 

[Ricko1966]

Helicoil , You can do it. They do or did make oversize self tapping inlet fittings, its ghetto,but it's not my carb. Okay I think I'd try a Tomco 471 fuel inlet. No tapping UT seals with 2 Owings and compression. It's less than a helicoil kit and more DIY friendly